What is a stored procedure?

A stored procedure is a precompiled set of SQL statements that reside in the database and can be executed by name. It can accept input parameters, return result sets or output parameters, and encapsulate business logic. Using stored procedures improves performance by reducing network round trips, allows the database engine to optimize execution plans, and centralizes logic for easier maintenance. It also enhances security by granting users execute rights on the procedure while restricting direct table access. Example: CREATE PROCEDURE GetEmployee @id INT AS SELECT * FROM Employees WHERE EmployeeID = @id; Then call it with EXEC GetEmployee 5. The procedure runs in O(1) time for the call itself, but the underlying SELECT’s complexity depends on indexes and data size.